1. Field of the Invention
The present invention relates to a connection device for connecting mounting rails in a double-T joint and includes an intermediate member and at least one receiving member connectable with the intermediate member. The intermediate member has two, extending substantially parallel to each other, legs and a connection section connecting the two legs for at least partially encompassing a first one of the mounting rails.
The at least one receiving member has two extending substantially parallel to each other legs and a connection section for connecting the two legs. In the at least one receiving member, a second one of the mounting rails, which butt-joins the first one of the mounting rails, is received. The at least one of the legs of the intermediate member has a plurality of, spaced from each other and located opposite each other, elementary receptacles for receiving the at least one receiving member.
2. Description of the Prior Art
Mounting rails are well known and are used, e.g., for connecting connection parts or conduit strings. Because of a large number of possible uses of the mounting rails, they are connected in a support framework by using attachment parts or connection devices.
E.g., in steel-clad or reinforced concrete halls, for providing flexible connection possibilities in constructional technology and for feeding of process media such as, e.g., current, compressed air, water, there are formed intermediate planes in form of grid ceilings formed by mounting rails and which are suspended from roof supports of a hall. The grid ceilings, which are formed of mounting rails, can be easily adapted to variable loads, e.g., for arranging of heavy conduits, or to particular static requirements by selection of corresponding mounting rails.
Usually, the grid ceilings include main girders extending in one direction and between which, sections of mounting rails as cross-girders in double-T joints are arranged, e.g., as supports or for stiffening of the grid ceilings. Grid ceilings and other frameworks, which are formed of mounting rails, provide a plurality of possibilities for securing, e.g., tubular conduits on the mounting rails with known connection parts such as angles and/or pipe clamps.
German Publication DE 100 00 092-A1 discloses a connection device for connecting mounting rails in a double-T joint and including a U-shaped intermediate member for encompassing a first mounting rail and at least one U-shaped receiving member fixedly securable to a leg of the intermediate member and in which a second mounting rail, which butt-joins the first mounting rail, is received. The connection device further includes a stirrup that serves as a securing element for the attachable mounting rail, is secured in undercuts provided on the free edges of the leg and secures the second mounting rail to the connection device with a rail nut that serves as attachment means.
The drawback of the connection device of DE 100 00 092-A1 consists in that only mounting rails, which have a certain height, can be connected with the first rail for forming a double-T joint. For different mounting rails having different heights, a plurality of differently formed connection devices are required which are expensive to manufacture and which require large logistic expenses from the manufacturer, dealer and user. When the known device is used, e.g., for forming a suspended grid ceiling, mounting rails with different heights, upon being connected, do not provide a continuous lower or bearing surface of the grid ceiling, e.g., for mounting of conduits in a substantially linear plane or for the arrangement of plaster plates, sheathing plates, or acoustic panels.
European Publication EP 1 201 936 A1 discloses a connection device for connecting mounting rails in a double-T joint and including one or more U-shaped intermediate members for encompassing a first mounting rail, and at least one U-shaped receiving member releasably secured on a leg of an intermediate member with a locking device and in which a second mounting rail, which butt-joins the first mounting rail is received. With a further receiving member and with use of a rail nut, which form fastening means, the second mounting rail can be secured to the connection device. The locking device has four elementary receptacles arranged about an inner thread and which are provided on each leg of the intermediate member, and four spigots provided on the receiving member and engaging the elementary receptacles. The locking device provides for rotation of the receiving member by an angle, which is multiple of 90°, for proper arrangement of the receiving member on the leg of the intermediate member.
The drawback of the connection device of EP 1 201 936 A2 consists in that for connecting different mounting rails having different height dimensions, several intermediate members should be arranged on the first mounting rail which, e.g., is not possible with a substantially horizontal grid ceiling without additionally arranging of vertical sections of mounting rails on the grid ceiling. Furthermore, with the known connection device upon use of mounting rails having different heights, only grid ceilings with a bottom flat bearing surface, e.g., for arrangement of plaster or sheathing plates can be produced. Placing of conduits in a substantially straight plane on the produced grid ceiling, when mounting rails of different heights are used, is not possible with the connection device of EP 1 201 936 A2.
Accordingly, an object of the present invention is to provide a connection device with which connection of mounting rails, which have different heights, is possible and which, at the same time, will be very flexible in its use.